Optical measurement methods for nanometer scale features have progressed rapidly in recent years with the introduction of several super-resolution techniques capable of surpassing the diffraction barrier. For example, Structured Illumination Microscopy can halve the resolution of a microscope by reconstructing a higher resolution image from several lower resolution images taken while varying an illumination pattern. In other examples, localization techniques have been used to emit only a portion of the fluorophores from a sample at any time. A resulting intensity profile then can be fit to localize the fluorophore with high resolution to produce near nanometer resolution in certain cases.
Common to all these techniques, however, is a need to acquire several images along with specialized illumination, fluorescent tags, or both, in order to reconstruct the higher resolution information.
There is also a need to acquire higher resolution information from telescopic systems. For example, in astronomical observations, particularly astrophysical measurements of binary stars, exo-planets, or accretion disks, the angular resolution of the measurement is particularly important. Working against these measurements are two factors: the seeing limit and the diffraction limit. The seeing limit arises from turbulent mixing of the Earth's atmosphere causing variations in index of refraction. These variations cause the image of a point to break up into a several blobs or speckles that move around rapidly. In addition to moving the telescope to space, techniques such as lucky imaging and adaptive optics have become highly effective at minimizing this limit to resolution. In contrast, the diffraction limit of telescopes is a function of the instrument itself, scaling linearly with the diameter of the telescope's aperture. Therefore, there is a need to improve the diffraction limited resolution of widefield telescopes.